We study the production and perception of song in the zebra finch, a species where males use song to attract and court females. The song that males perform as adults is memorized from a tutor early in development and refined through a process of sensorimotor learning until eventually it becomes highly stereotyped or “crystallized” around 90 days of age. Females can use these adult songs to discriminate between different males as well as to assess the quality of potential mates.
Although the adult songs of male zebra finches are highly stereotyped from one rendition to the next, they are not completely static. Rather, males alter their songs depending on their audience, performing a faster, longer and more stereotyped song when they perform for females than when they sing in isolation. In addition, the activity of single neurons in a cortical-basal ganglia pathway, known as the anterior forebrain pathway or AFP, is less variable during the courtship song than when males sing alone. By recording from the inputs and outputs of the basal ganglia nucleus Area X, the first step in this pathway, I have found that this context-dependent difference in variability appears to arise within the basal ganglia proper. We are currently continuing to investigate the circuit mechanisms by which this variability arises.
Females can use song to identify individuals, gain information about the intention and behavioural state of the signaler and even to choose a mate.However, we have little understanding of how higher centers in the brain are able to accomplish these complex perceptual tasks. I have previously found that females show strong preferences for courtship song over non-courtship song and the strength of this preference is influenced by the social experience of the female. Moreover, a higher-level auditory area shows differential gene expression in response to courtship and non-courtship song, indicating that it may be important for the perception of these and other social signals.Using electrophysiology, behavioral analysis, immunocytochemistry and computational methods, our work investigates how the brain processes and perceives social signals, and how both perception and the underlying neural mechanisms are shaped by social experiences as well as evolution.